1. Field of the Invention
This invention relates to a laser irradiating apparatus, especially for the medical purposes.
2. Description of the Prior Art
As is well known, the laser irradiating apparatus is used for medical purposes and produces excellent results. The laser irradiating apparatus is called a surgical laser and in general it consists of a power supply, a laser head and a light guide. FIG. 1 is a block diagram showing a conventional surgical laser. As illustrated, the shaft 2 is vertically arranged on the power supply box 1, and the laser head 3 is fixed horizontally on the shaft 2. In the laser head 3, a laser resonator is contained.
At the end of the laser head 3, the light guide 4 is mounted and fixed. Light guide 4 leads laser beam generated from the laser resonator to the desired target. When CO.sub.2 laser is used for the said resonator, light guide for articulated arm is generally used.
The light guide for the articulated arm is plural pieces of freely rotatable mirrors joint structure connected through hollow pipes, inside which the said laser beam is reflected and directed.
When the surgical laser is used for a surgical operation, the apparatus is installed in an operating room so that the light guide tip is positioned above the affected part for the operation. An operator holds the light guide tip (hand piece) to perform the operation. As, in this connection, laser head 3 is horizontally located in this apparatus, the operating table could be conveniently kept away from the power supply box 1 even if the apparatus is installed as above-mentioned. If this apparatus had been installed close to the operating table 13, it would have hindered any action of an operator, assistant doctor and nurses during the operation. Accordingly, it was desired to separate the apparatus as far as possible from the operating table. Also, as above-mentioned, the laser head 3 is horizontally located in this apparatus and it is possible to position the tip portion of the head above the operating table even if power supply box 1 is installed away from the operating table. Hence, a comparatively small size, one with a short horizontal arm 41 could be conveniently used for the articulated arm light guide 4. Because when the articulated arm light guide 4 was larger, the horizontal arm 41 would be inevitably heavier and the inertia moment became higher, thus lowering the maneuverability
Since, however, the laser head 3 arranged horizontally was supported by a single shaft 2 only in this conventional apparatus, the laser head 3 could not be soundly fixed. Therefore, any external impact and deterioration with age, etc. tended to cause strain or deflection, resulting in troubles to the optical system of the resonator, etc.
Also, since the light guide 4 was provided at the end of the laser head 3, the operating range by means of the apparatus was naturally limited, viz. the operating range was limited to an area in which the light guide 4 is available to operate round the tip of laser head 3. Specially when performing surgical operation near a power supply box, or when one operator performed surgical operation while operating the apparatus inconveniences occurred. So, it was not suitable when one operator gave outpatients medical treatment by himself. When a smaller articulated arm was used, these defects were worse.
Further, since as mentioned before the laser head was fixed horizontally, a space occupied by the apparatus became very large and it was inconvenient especially when the apparatus was stored or moved.
Although not illustrated, an apparatus similar to the above apparatus is proposed. It has a rotatable horizontal arm fixed to the shaft which is vertically fixed on a power supply box, and a laser head is fixed onto the horizontal arm. The laser head rear end is horizontally supported and fixed at one point of the tip of horizontal arm, and articulated arm light guide is fixed at the laser head tip.
It goes without saying that this apparatus has the same effect as the said apparatus. Since, however, laser head arranged horizontally was supported by a single supporting point in this apparatus strain or deflection tended to occur at the laser head causing troubles to the optical system of the resonator.
In addition, use of an articulated arm light guide with multi-joints causes strain or deflection to the laser head because of the weight and as such a light guide was not suitable to use. Also, it might have caused unbalance of the apparatus weight. Accordingly, under the present conditions, light guide with multi-joints, viz. with much degrees of freedom cannot be used for this apparatus. Therefore, the maneuverability is not so good nor wide range of operation can be secured.